44 p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



42. P. (Donkinia) carinatum Donk. (1858). — V very convex, unilaterally tapering from 

 the middle to the acute end,s. L. 0,i to 0,13; B. Ooi to 0,oi3 mm. Median line almost diagonal in 

 the middle and then closely following the convex margins. Transv. and obi. striee "/is- '^^lin i" 

 0,01 mm. — Donk. T. M. S. VI p. 23 PI. Ill f. 5. Donhinia car. Eale in Pritch. Inf. p. 921 

 (1861). Per. IX f. 6. 



Marine: Sea of Kara! Davis Strait! North Sea! Balearic Islands! Japan, fossil (Brun coll.)! 



43. P. speciosum W. Sm. (1852). — V. linear, with unilaterally rounded ends. L. 0,i8 to 

 0,27; B. 0,023 to 0,025 mm. Median line strongly excentric towards the ends. Transv. and obi. 

 striffi 17,6- "/i7. ^"/w. '"/i8. '7„ in 0,oi mm. — W. Sm. Ann. Mag. N. H. [2] IX p. 6 PL I f. 3. 

 B. D. I p. 63 PL XX f. 197. Per. II f. 13 to 16. 



Marine: North Sea! Mediterranean Sea! Red Sea! Java! Sumatra! Labuan! China! Port 

 Jackson! Barbados! 



Var. gracilis Pbk. (1891). — More narrow. L. 0,25; B. 0,oi5 mm. Transv. and obL strise 2%g 

 in 0,01 mm.' Per p. 6 PL II f. 19. 



Marine: Sumatra (Per.). 



Var.? Javanica Per. (1891). — L. 0,07; B. 0,02 to 0,23 mm. Transv. and obi. strise ^"/jg in 

 0,01 mm. — Per. p. 6 PL II f. 17, 18. 



Marine: Java, Sumatra (Per.). 



Var.? abrupta Per. (1891). — Same as var. javanica, but with obliquely truncate ends. — Per. 

 p. 6, PL II f. 11. 



Marine: Java, Sumatra (Per.). 



Var. mediterranea G-run. (1880). — Linear, with unilaterally rounded ends. L. 0,2 1 to 0,32; 

 B. 0,018 to 0,0 2 6 mm. Median line strongly excentric, coincident for a considerable distance witli 

 the convex margin. Transv. and obi. strife '^'Vis.s) ''lui 'Vi* in 0,oi mm. — P. ohscurum var. medit. 

 (5^RUN. A. D. p. 49. Per. II t 5. 



Marine: Mediterranean Sea! Seychelles (Grun.), Java! 



Var. pulchra Grun. (1860). — V. and median line as in var. medit. L. 0,3 to 0,6; B. 0,023 

 to 0,04 mm. Transv. and obi. striae '7,0, '''/,i, 'Vm 'V22 in 0,oi mm. -- P. pulchr. Grun. Verb. 

 1860 p. 556 PL VI f. 2. Per. I f. 8. 



Marine: North Sea! Red Sea (Grun.), Java! Sumatra! 



Var.? fortuosa Cl. (1881). — V. lanceolate, slightly sigmoid, with unilaterally rounded ends. 

 L. 0,076; B. 0,012 to 0,013 mm. Median line strongly sigmoid and very excentric. Transv. and 

 obi. striEe '"/jo in 0,oi mm. — P. tort. Cl. N, R. D. p. 5 PI. I f. 6. Per. II f. 12. 



Marine: Balearic Islands! 



44. P. majus Grun. (1880). — V. lanceolate, gradually tapering from the middle to the 

 obtuse ends, slightly sigmoid. L. 0,2 to 0,4; B. 0,024 to 0,052 mm. Median line nearly straight 

 in the middle, excentric towards the ends. Oblique strife form in the middle of the valve an ob- 

 tuser angle than on other parts of the valve. Transv. and obi. striae '^'^/is.j (Grun.) '7,3, "/j,, 

 i8/j3, -<•/,, in 0,01 mm. — P. speciosum var.? major Grun. A. D p. 49. P. of fine var. interruptum 

 Per. PL IV f. 1 to 3. PI. majus Icon. n. PL IV f. 15. 



Marine: Mediterranean Sea! Sumatra! 



45. P. Heros Cl. N. Sp. — V. lanceolate, slightly sigmoid, gradually tapering from the 

 middle to the obtuse ends. L. 0,4; B. 0,08 5 mm. Median line straight, somewhat excentric towards 

 the ends. Transv. and obi. striai 'Vio in 0,oi mm. — PL IV f. 20. 



Marine: Macassar Straits (Grove's Coll.)! 



This form is closely allied to P. majus, being somewhat broader. The strias are coarser and 

 in the same direction in the middle as elsewhere. It is also nearly akin to P. formosum v. longis- 

 sima, which is more sigmoid and has a more excentric median line. 



